Spring Making Made Easy

When I first started gunsmithing, spring making was one of intrigue and mystery. Of course, this was before American Gunsmith and other media existed. Articles on the subject seemed vague on certain things, as if the author didn’t want to give up his "secret recipe." One notable tidbit of information I found in a compilation of gunsmithing helpful hints was (paraphrased) "Take an oil can, make a dent in it, place your part on the can, cover with oil, and light it afire.

When it burns out, cover with lime, and you either have a spring or you don’t." Huh? Well, the good new is, at the end of this article you actually will have a spring with no element of luck needed, provided you follow the procedures. Among the most important items is your material. I keep on hand various sizes, widths, and thicknesses of spring steel available through Brownells.

I also stock sheets of 12×12" annealed steel sheets of various thicknesses from Mc Master- Carr (McMaster.com, Sheets in sizes of 0.020, 0.025, and 0.030 cover just about all I need. When do you make a spring? Most springs I make are simply not available anymore, or urgency in the job being completed demands it, or in the unlikely event an ordered replacement spring turns out not to be a spring. For example, some time ago I ordered an extractor for a Savage 340, which is a small, flat spring.

Upon installation, pushing it in to install the retaining pin collapsed it. Because it was not a spring as it was supposed to be, I had to make one and did so a little stronger than necessary. It does not matter what shape your spring is to be, the procedures are all the same. I always cut my spring stock a little long, with one end being my reference point, so as I’m shaping it I know the other end will at least be long enough and have to be trimmed prior to final fitting and heat treating.

Prior to shaping, if your stock is too thick (which is probably the case) you’ll have to take it down to the proper thickness. With a surface grinder, take it down before cutting the outline utilizing all the material on the magnetic chuck. Otherwise, do it by hand. I’ve used both methods and purchased a used surface grinder just for this purpose. Layout the part using a layout fluid such as Dykem to mark the outline of your future spring.

Some of the spring making material will be wider than the majority of your part so you will have metal to remove. An example would be a Vspring for a muzzle loader with a retaining stud. There are several ways to do it, depending on the machinery you have available. You can use a mill, a drill press with a small bit to drill around the out-

line, or a Dremel followed by a file. It’s also possible to use several hand files for the whole thing but not recommended as that’ll wear you out. Of course, it eventually will come down to the hand files, so have a good set. I cut the thin sheets I use for making a spring with aviation snips as a Dremel cut-off wheel heats up the metal too much. Drill and tap a hole if needed for a flat spring.

With a Vspring, measure for the proper location on the bend and put it in your vise with appropriate vise jaws, I use bronze vise jaws from Brownells to prevent marring the part. Apply heat from a propane torch to the part and start bending using a ball peen hammer until it’s at least ninety degrees.

I have fabricated some tools to assist in shaping Vsprings, such as a metal block for drilling and tapping two holes for a strap of metal to hold either the part or a hardened rod placed to put special bends into the part. I also use a metal block with a relief cut the same size as the rod to make these bends. To cut a slot for the hammer stirrup, I use a Dremel cut-off wheel very carefully.

In studying old springs, it appears that this part of the spring is probably hot forged in a die and I’ve found it’s the most difficult part to Once the part has been shaped to final size and all cuts made, remove all tool marks. Failure to do so will lead to the part failing in the future. With the part shaped and polished, the next step will make this part a spring. The heat source needed depends on the size your final spring is to be.

Most springs require oxygen/acetylene and small, thin parts work with MAPP gas. You will have to make that call when you are doing it. If it is difficult to keep hot and red, you need a hotter heat source. Large parts can be wired up to be heated. I heat small parts on a metal strap approximately 9/64 thick. Sometimes I use direct heat and others I use indirect heat from the bottom, depending on the size.

You will need a cooling medium, I have been using Tough-Quench (Brownells 083-027-032) for all my spring making. I pour it into a metal can for large parts and for small parts I use a one cup measure or an aerosol can lid so I can recover the part easily. The part is ready for the first of two make look like a factorymade spring. heat treatments. Take it to "bright red" (approximately 1500 degrees) and hold it there for a few seconds.

Immediately quench it in your oil, stirring it around and getting it uniformly cool. With a large part, such as a Vshaped mainspring, you can actually feel and hear the agonizing of the metal molecular structure chang-

ing. It will pop and seem to wiggle. This is why the part is brittle after quenching. The molecular structure is not aligned and has been very disrupted. Remove your part from the quenching oil, let the oil drain off, then gently wipe off the excess. Your part will be a dull silver and black. Remove the black material with light sanding, steel wool, and a Cratex wheel in one direction. The Cratex wheel will take it to a highly shiny, polished appearance.

Do this carefully as your part will be brittle and prone to breakage. The next step is where the polishing really shines (pun intended.) Temper the brittle, agitated part and align its molecular structure by heating it to a precise temperature and color. Your heat for this final step does not need to be as hot. I use MAPP or propane depending on the size. I place one end of apiece of metal 1 1/2" wide, 10" long, and 9/64" thick into my vise.

Apply a small amount of heat to warm it up if the shop is chilly as you don’t want to shock it before applying the heat treatment. Lay the part onto the metal so as much of it is in contact as possible. Most parts lay on their sides while small flat parts lay flat.

Once the part is on the flat piece of metal where you want it and you can see it comfortably and from straight on, apply the heat to the underside of the metal strap in the vise, keeping it moving around the perimeter of your part and slowing bringing it directly underneath the part. As you do this, depending on the size, change of color can happen very rapidly, so be alert. Colors will range from dull gray, straw yellow, purple, then blue. When it starts to turn purple, you are very close.

Blue, or 575 degrees, is where you want to be. When it immediately turns blue, flick the part off the metal and on to your bench. Let it completely cool before testing. I know you’ll be anxious but patience is a virtue when doing this. Once cooled to room temperature, place your spring into a padded vise. With a Vspring, slowly close and open the vise. The spring legs should follow the vise out and retain its original shape without breaking. Flat springs can be put in the vise and then bending them.

If these parts bend and snap back, congratulations, you’re a spring maker. If it breaks, something in your heating process went awry. Don’t despair, as I’ve had failures too. It’s a learni ng process. Once learned, you’ll be glad you stepped into another facet of gunsmithing and can provide another service for customers. AG